One commercially available type of brake drum cleaning apparatus includes a metal canister or hood which is mounted on a movable base and adapted to surround the brake drum. The back of the canister is provided with a flexible closure member which is drawn about the back of the brake drum; and the solid canister includes, in its side wall, a window for viewing the operation, and an opening in the side wall (or the end wall) equipped with a piece of material in the form of a sack which serves as a hand and arm protector permitting the operator to have hand access to the interior of the canister for removing the brake linings or directing forced air to clean the brake drum. In this embodiment, air is brought to the interior of the canister by means of quick disconnect fittings rigidly attached to the end wall of the canister; and the canister is evacuated continuously by means of a vacuum cleaner equipped with a HEPA (high efficiency particulate air) filter.
Another embodiment has a wire cage with a clear plastic cover equipped with a series of access apertures in the form of small circular reinforced ribs with slits in the form of "x's" to form valves which allow an air nozzle or tube to be inserted for clearing the drums with the hard valve on the outside of the enclosure and free to be moved to another access aperture. These devices do not permit the operator to have protected hand access to the brake drums for removal. It is also believed to be undesirable to have the air nozzle free to be operated outside the encapsulator because of the possibility of creating dust with entrained asbestos particles due to the hazard involved.
The present invention provide improvements over existing commercial apparatus for cleaning brake drum assemblies by providing a system which is lower in cost, lighter in weight (and, therefore, more maneuverable), and which facilitates access to the interior of the enclosure and enhances the maneuverability and field of view of the operator within the enclosure. The encapsulator of the present invention includes a cage in the form of a ribbed drum made of welded metal rod which is light in weight and provides full visibility to the interior. A cover of clear, continuous vinyl material encapsulates the cage, fully sealing the cylindrical wall of the cage as well as the distal end (i.e., the end remote from the brake assembly). The proximal end of the vinyl cover is provided with a bungee cord or draw string and defines an opening for receiving a brake drum assembly. After the brake drum assembly is positioned within the encapsulator, the bungee cord is pulled tight about the rear of the drum assembly.
A pair of gloves are integrally formed in the closed end of the cover, permitting the operator to extend both hands into the interior of the enclosure to disassemble the brake drum or remove the brake lining. The closed end of the vinyl cover is a wall of generally frustoconical shape which permits the operator to move his hands back and forth as well as laterally in the encapsulator. The central-most portion of the movable end wall of the cover is flat and has an air gun assembled to it, with a hand-actuated valve on the outside, and a discharge nozzle on the inside so that the air valve cannot be removed and inadvertently discharged into the atmosphere. A conventional vacuum cleaner with an HEPA filter is used to evacuate the enclosure.
Other features and advantages of the present invention will be apparent to persons skilled in the art from the following detailed description of a preferred embodiment accompanied by the attached drawing wherein identical reference numerals will refer to like parts in the various views.